1. Technical Field of the Invention
The present invention relates to a telecommunications network and, in particular, to the provision of a distinctive ring tone for a calling party subscriber within such a network.
2. Description of Related Art
With the introduction of Common Channel Signaling (CCS) telecommunications systems, a number of advanced telecommunications subscriber features have become available to subscribers. Using packet and non-circuit communications modes, a Signaling System No. 7 (SS7) telecommunications network utilizing the CCS standard, for example, allows two telecommunications exchanges to communicate data other than mere voice with associated telecommunications subscribers. One such subscriber feature or capability includes a calling line identification (CLI) subscriber feature.
A directory number associated with a calling party subscriber is included within a call setup signal, such as an Initial Address Message, and transported from an originating telecommunications exchange to a terminating telecommunications exchange serving a called party subscriber terminal. The terminating telecommunications exchange then extracts the included directory number and displays it at a customer premise equipment (CPE), such as a caller ID display unit, attached to the called party subscriber terminal. The called party subscriber is then able to ascertain the identity of the calling party subscriber before choosing to answer the incoming call connection. Furthermore, the terminating telecommunications exchange is also able to selectively screen incoming call connections by rejecting, accepting, or rerouting the incoming call connections depending on the directory numbers associated therewith. Accordingly, by defining an allowed list and/or disallowed list of directory numbers, the terminating telecommunications exchange is able to selectively screen incoming call connections without requiring manual interventions or instructions.
Although a number of screening or filtering subscriber features, as described above, have been introduced, the features or services have been focused mainly on the terminating side of a call connection. As a result, unless a calling party subscriber is already aware of the identity associated with a dialed directory number, the calling party subscriber remains clueless as to the identity of the called party subscriber until the call connection is answered by the called party subscriber. For example, tele-marketers wishing to sell long distance carrier service usually do not want to solicit business from non-resident customers or to bother people at work. However, not knowing what type of subscribers are associated with their potential customer directory lists, tele-marketers nonetheless have to dial each number only to find out that an associated subscription or line is a business number.
As a solution for the above problem, a calling party subscriber terminal can be equipped with a connected line identification display unit. In a manner similar to the calling line identification feature, a connected line identification presentation subscriber feature then displays, for example, the text description or name associated with a dialed directory number at the attached display unit. The calling party subscriber may then review the displayed information and ascertain the called party subscriber type. As an illustration, if the displayed text shows "ABC Inc.", the calling party subscriber may assume that the dialed number is a business number.
Such an implementation is undesirable because a call connection has already been established and the called party subscriber terminal has already been alerted (rung). Terminating the call connection abruptly thereafter by hanging-up the phone might, for example, further irritate or bother the called party subscriber. It further requires the calling party subscriber terminal to be equipped with a special display unit and means for communicating such data with the originating telecommunications exchange in speech mode. Moreover, other than from the displayed text description, such an implementation still fails to inform the calling party subscriber whether the called party subscriber terminal is associated with a wireline, wireless, residential, or business number.
Accordingly, there is a need for a mechanism to enable an originating telecommunications exchange to ascertain the subscription type associated with a called party subscriber terminal and to inform a calling party subscriber associated thereto.